<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
		<style type="text/css">
			#test{
				width: 150px;
				height: 150px;
				border-radius: 50% 50%;
				box-shadow: 0 0 0 20px red ,
				 0 0 0 40px blue,
				 0 0 0 60px green;
				margin: 200px;
				border: 5px solid black;
				padding: 30px;
				box-sizing: border-box;
				}
				/*内嵌
				 */
				#test2{
				width: 150px;
				height: 150px;
				border-radius: 50% 50%;
				box-shadow: 0 0 0 20px red inset,
				 0 0 0 40px blue inset,
				 0 0 0 60px green inset;
				margin: 200px;
				border: 5px solid black;
				padding: 30px;
				box-sizing: border-box;
				
				}
		</style>
	</head>
	<body>
		<div id="test">
			
		</div>
		<div id="test2">
			
		</div>
	</body>
</html>
